Tone generator



April 4, 1934. v. E. JAMES 1,956,353

TONE GENERATOR Filed Feb. 1. 1932 /o v- 6o-4c m ur EECT/F/EE PoLAE/Zsv 4% TUNED TO 60* cunesNT /0 6 Toms a ourrur fil/ I l 2000 2000 m z g I N l M I I g 9 N L I -*o I U 8 l H 5 ITL'LJ'ETL t D 1- UITH'IL]. E. James Patented Apr. 24, 1934 TONE GENERATOR Virgil E. James, Chicago, 11]., assignor, by mesne assignments, to Associated Electric Laboratories, Inc., Chicago, 111., a corporation of Delaware 7 Application February 1,

9 Claims.

The present invention relates to tone generators in general, but, it relates, more particularly, to that class of tone generators employing electro-magnetic relays as the means by which the tone is generated.

The principal object of the present invention is to provide apparatus which will function on commercial alternating current to generate a tone suitable for the many uses to which such a tone is put to advantage in electrical systems,

and to provide an apparatus which is manufactured at a very low cost compared with known types of tone generating equivalent without sacrificing any reliability of performance.

This object is achieved in the manner about to be described in conjunction with the associated single sheet of drawing in which the apparatus of this invention is diagrammatically depicted.

The conductors 1 and 2 of the drawing are adapted to be connected to a source of commercial alternating current, which, it is being assumed, is a source of 110 volt 60 cycle current. Relay 3, which is bridged across these conductors, may be any well-known type of polarized relay, the armature of which can be adjusted to vibrate in synchronism with the alternations of the alternating current.

Also bridged across the conductors 1 and 2 is a well-known type of rectifying circuit employing dry disc rectifiers. Relay 5 has the terminals of its winding permanently connected to the positive and negative terminals of the rectifier circuit. Therefore, when the'conductors l and 2 are first connected to the source of alternating current the alternating current is rectified and supplied to the winding of relay 5 as direct current, whereupon relay 5 energizes and attracts its armatures 6 and '7. The energization of relay 5 is slightly delayed, in the well-known manner, by the provision of a copper slug on the armatureend of its core, this slug being represented in the drawing by the black portion a the upper end of relay 5.

The attraction of armature 6 of relay 5 connects the contacts of armature 4 of relay 3 to the tone output terminal 11, while the armature '7 of relay 5 opens the shunt of the winding of relay 8 and connects that winding to the positive terminal of the rectifier in parallel with the winding of relay 5. Relay 8 thereupon energizes and attracts its armature 9, which armature strikes its weighted contact and causes that contact to vibrate for a period before coming to rest in engagement with the armature. When the 55 contact comes to rest in engagement with arma- 1932, Serial No. 590,096

ture 9, the relay 5 is short-circuited causing this relay to retract its armatures, thereupon at armature 6, opening the tone circuit and at armature 7, opening the energizing circuit of relay 8 and closing the shunt circuit thereof. This shunt circuit, as is well known, causes relay 8 to slowly deenergize and slowly retract its armature 9. The retraction of armature 9 opens the shortcircuit of relay 5, permitting that relay to again close the tone circuit and to again close the energizing circuit of relay 8, whereupon armature 9 starts the vibration of its contact, which, after an interval, comes to rest and again short-circuits relay 5. Relay 5 again retracts its armatures, opening the tone circuit and the energizing circuit of relay 8. This cycle of operations is continued as long as the conductors 1 and 2 remain connected to the source of alternating current, thereby causing periodic interruptions in the tone circuit, which interruptions will occur at intervals of a length depending upon theposition of the weight on the contact of armature 9 of relay 8. A relay of the character of relay 8 is shown and described in United States Letters Patent No. 1,727,968, granted to John Erickson,

September 10, 1929.-

The armature 4 of relay 3 engages its right hand contact each time the relay 3 energizes on each positive half-wave, for instance, of the alternating current and engages its left-hand contact each time that relay energizes on each negative half-wave of the alternating current. Each time armature 4 engages one of its contacts, it connects the conductor 1 to the output terminal 11 during such time as relay 5 is energized and is holding its armature 6 in the attracted position. Interruption of the flow of alternating current by armature 4 causes a tone to be generated which can be supplied to any desired circuit by the connection of that circuit to the terminals 10 and 11.

' Since, as has been stated, relay 3 is tuned to vibrate its armature in synchronism with the cycle current, armature 4 will be attracted in one direction sixty times per second and attracted in the other direction sixty times per second, thereby passing between its contacts one hundred and twenty times per second and interrupting the alternating current one hundred and twenty times per second, which interruptions are sufiiciently rapid to cause the generation of an easily audible tone.

If the contacts of armature 4 were directly connected to output terminal 11, the output would be a continuous tone. However, with the tone circuit being interrupted by armature 6 of relay supply circuit 5, an interrupted tone is secured, which type of tone is the more desirable one for most purposes.

From the foregoing, it will be appreciated that the present invention provides a desirable, efficient and reliable means for generating an interrupted tone from a commercial source of alternating current.

The invention having been thus described, what is considered new and is desired to have protected by Letters Patent is described in the claims which follow.

What is claimed is:

1. In combination, a circuit having alternating current flowing therein, means operated by said alternating current for interrupting the flow thereof to generate an audible tone in said circuit, means for rectifying a. portion of said alternating current, and means operated by the rectified current for periodically and momentarily interrupting said tone.

2. In combination, a circuit having alternating current flowing therein, means operated by said alternating current for interrupting the flow thereof to generate an audible tone in said circuit, means for rectifying a portion of said alterhating current, and means operated by the rectifled current for periodically and momentarily interrupting' said tone, said last means comprising a pair of direct current relays, one of which has means for closing and opening the energizing circult of the other upon energizing and deenergizmg, respectively, and means for closing and opening said circuit upon energizing and deenergizing respectively, the other of said pair of relays having means for slowly closing and quickly open ing, upon energizing and deenergizing, respectively, a shunt circuit about said one relay to cause a delayed deenergization and a quick reenergization of that relay.

3. In combination, an alternating current supply circuit, an output circuit, one leg of said supply circuit being permanently connected to one; leg of said output circuit, and. a polarized relay operated by the alternating current in. said supply circuit to intermittently connect the other leg of said supply circuit to the other leg of said output circuit to thereby generate. a tone in said output circuit, said relay comprising a winding connected across the legs of said supply circuit, anarmature tuned to vibrate atthe period, of the alternating current and connectedto one of said other legs, and a contact arranged to be engaged by said armature and connected to the second of said other legs.

4". In combination, an alternating current supply circuit, an output circuit, one leg of said being permanently connected to oneleg of said output circuit, and a polarized relay operated by the alternating current in said supply circuit to connect, intermittently and at twice the frequency of said alternating, the other leg of thesupply circuit to the other leg of said output circuit to. thereby generate a tone in. said output circuit; having twice the frequency of said alternating current, said relay comprising. awinding bridged across the two legs of said supply circuit, an armaturetuned to oscillate at the frequency 011 said alternating current and connected tothe second other leg and arranged to be engaged. by said armature as it vibrates, one contact being engaged at each end of the armature stroke.

operated by the alternating current in said supply circuit to intermittently connect the other leg of said supply circuit to the other leg of said output circuit to thereby generate a tone in said output circuit, said relay comprising a winding connected across: the legs of said supply circuit, an armature tuned to vibrate at the period of the alternating current and connected to one of said other legs, a contact arranged to be engaged by said armature and connected to the second of said other legs, and means for periodically interrupting' said output circuit to cause said tone to be periodically interrupted.

6. In combination, an alternating current supply circuit, an output circuit, one leg of said supply circuit being. permanently connected to one leg of said. output circuit, and a polarized relay operated by the alternating current in said supply circuit to intermittently connect the other leg of said supply circuit to the other leg of said output circuit to thereby generate a tone in said output circuit, saidrelay comprising a winding connected across: the legsoii said supply circuit.

an armature tuned to vibrate at the period or the alternating current and connected to one or said other legs, a contact arranged to be engaged by said armature and: connected to the second of said other-legs, direct current means for periodically interrupting. said output circuit to cause said tone to be periodically interrupted. and circuit means, including a rectifier for rectifying a portion of said. alternating current, for supplying direct current to said periodic interrupting means. i

'7'. In combination, an alternating current supply circuit, an output circuit, one leg or sudden}:- ply circuit being: permanently connected to one leg of said output circuit, and a polarized relay operated by the alternating current in said, supply circuit to. intermittently connect thev other leg of said supply circuit to the other leg of said output circuit to thereby generate a tone said output circuit, said relay comprising a winding connected across the legs. of: said supply circuit, an armature tuned to. vibrate at the period of the alternating current and connected ,to' one of said other legs, a contact: arranged to be' engaged bysaid armature and connected to the second of said other legs, a source of direct current, a\ direct current relay having its" winding permanently connected to said source and having contacts in said output circuit which are closed whenever direct current is flowing'through the winding of said direct current relay, and. means operated by said direct current relay for periodically and momentarily shunting the direct current around the winding of the direct current relay to cause that relay to periodically and momentarily open its contacts, thereby periodically and j momentarily interrupting'said' tone. 1

8. In combination with; a two-wire circuit having alternating. current of a; known frequency flowing therein, said clrcuitihaying an input end and an output end, a polarized relay bridged across the input end of said circuit and energizing and deenergizing with each alternation, of said current, said relay having contacts in one side of the output end of said circuit tuned to the frequency of said alternating current, which contacts are closed and opened upon each energization and deenergization of said relay, thereby interrupting the flow of alternating current inthe output end of said circuit and generating a tone therein of twice the frequency of said alternating current, a rectifier also bridged acrossthe rent, an output circuit, means connected to the input circuit and operated by current from said source for generating alternating current in the output circuit of higher frequency than that in the input circuit, and means controlled over the input circuit for periodically interrupting said output circuit.

VIRGIL E. JAMES. 

